Federal authorities are attempting to identify the source of a letter that warns of the potential for violence by employees within the probation department of U.S. District Court. Authorities say they might prosecute whoever is found responsible for writing and circulating the missive to judges.

The one-page letter, typed on stationery from the probation department, was captioned "Violence in the Workplace" and stated that tensions in the office were so high that "someone could snap." Some court officials viewed the letter, which allegedly was from "Concerned Probation Staff Members," as an awkward cry for help, but others interpreted it as an illegal threat.

Copies of the letter appeared last month in the mailboxes of Chief Judge Norma Holloway Johnson and other officials at the Washington courthouse. Johnson reacted immediately, convening a meeting with probation department employees Sept. 24 in which she said she would talk with anyone about problems.

At the same time, the U.S. Marshals Service began attempting to find out where the letter originated to determine whether criminal charges were warranted. One source said the letter to Johnson was being checked for fingerprints.

"We don't know where this came from," said Richard A. Houck Jr., the court's chief probation officer. "I hope against hope it didn't come from one of our current employees. . . . The way this has come to the court's attention is totally inappropriate and probably illegal because it's a threat."

The probation workers, who have offices on the second floor of the courthouse, are key players in the court's operations, supervising 1,500 area convicts. They also interview hundreds of convicted defendants, victims and others each year while compiling reports they provide to aid judges in sentencing. The office has about 60 employees and is a branch of the court.

Johnson was not available for comment last week. U.S. District Judge Gladys Kessler, who was filling in as chief judge, said she believes "the courthouse is a safe and secure working environment." No one is authorized to carry guns into the building, which has metal detectors at each entrance, Kessler said. She declined comment on any troubles within the probation office.

The letter contends that many probation department employees have left the office or are planning to quit because of stress.

Houck said he could not comment on specific personnel matters but acknowledged some discontent. He said he is heading "an honorable, decent organization that is trying to do a tough job" with many stresses. Supervisors met with employees last week to offer help and identify problems, he said.